1. Field of the Invention
The present invention relates to a display panel and a manufacturing method of the same, and more particularly, to a display panel which can detect a touch position derived from a user's touch and can prevent erroneous touch position data from being generated even when physical defects arising from a processing deviation or a cell gap deviation are present, and a manufacturing method of the display panel.
2. Description of the Related Art
A touch panel is an input means installed on an uppermost portion of a display device, such as a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) or an electroluminescence display (ELD), to detect contact with a finger or a touching object, such as a stylus, so that the user may select one of a number of areas in which information is displayed on the screen of the display device.
Touch panels fall into two categories according to the operational principle used, namely, capacitive-type touch panels and resistive-type touch panels. In the capacitive-type touch panel, a transparent conductive film or a transparent conductive glass plate is repeatedly charged and discharged, as a small amount of charge accumulates between a pen-type input device, e.g., a stylus, and the transparent conductive film, and the amount of charge is detected to obtain coordinate values of the touched point. In the resistive-type touch panel, a voltage is applied between two conductive films facing each other, a user presses a screen to make the two conductive films contact each other, and a change that occurs in the voltage or current at a contacted point between the two conductive films is detected to read coordinate values of the contacted point.
Since the capacitive-type touch panel is disadvantageous in that it is necessary to supply electricity to a stylus for the capacitive-type touch panel, a resistive-type touch panel based on an analogue input method has recently been put into wide use. Here, the resistive-type touch panel may be integrated with a liquid crystal display panel, thereby preventing degradation in the luminance of the liquid crystal display panel.
The touch-panel-integrated liquid crystal display panel includes a first sensor line and a second sensor line formed on a TFT substrate in horizontal and vertical directions to detect a first coordinate for a position of an input point and a second coordinate for a position of the input point. In addition, the touch-panel-integrated liquid crystal display panel includes sensor pads formed on the TFT substrate and a sensor spacer and a sensor electrode formed on a color filter substrate to make the first sensor line come in contact with the second sensor line in response to pressure applied by a finger or stylus.
A height difference between sensor spacers formed on either the TFT substrate or on the color filter substrate may occur because of variations in dimensions arising from manufacturing processing variations. A deviation in the thickness of a cell gap, the gap between the TFT substrate and the color filter substrate of the display panel, may also occur. For these reasons, a contact between the sensor electrode and the sensor pad may undesirably occur even before a user touches the display panel, thus giving a false indication of a location of pressure application.